Hydroxy-L-proline is one kind of modified amino acids having a structure wherein a hydroxyl group is introduced into L-proline. It has 4 kinds of isomers due to the difference in the site into which the hydroxyl group is introduced (the 3-position or the 4-position carbon atom), and the difference in the spatial configuration of the hydroxyl group (trans configuration or cis configuration). Among the isomers of hydroxyproline, cis-4-hydroxy-L-proline is a substance useful as a starting material of a synthetic intermediate for pharmaceutical products such as carbapenem antibiotic, N-acetylhydroxyproline utilized as an anti-inflammatory agent and the like.
As a production method of cis-4-hydroxy-L-proline, a method of organic synthesis of a cis-4-hydroxy-L-proline derivative from a trans-4-hydroxy-L-proline derivative has been proposed (patent document 1). However, it has a problem in that a trans-4-hydroxy-L-proline derivative, which is the synthesis starting material, itself is expensive. While methods of producing cis-4-hydroxy-L-proline from L-proline by using microorganisms such as the genus Helicoceras and the like have also been proposed (patent documents 2 and 3), the production amount is extremely as low as 0.65 g/L, and is not practical.    patent document 1: JP-A-2005-112761    patent document 2: JP-B-3005085    patent document 3: JP-B-3005086